Epilepsy is one of the most common neurological disorders affecting women of childbearing age. Poor pregnancy outcomes are increased in these women and their children. The proposed studies will increase our knowledge on multiple levels to improve care and reduce adverse outcomes in these mothers and children. An overall goal of this study is to establish the relationship between antiepileptic drug exposure and outcomes in the mother and child as well as describe and explain the variability in antiepileptic drug exposure and response.